Fiber polymer composite

ABSTRACT

The claimed material relates to a fiber and polymer composite having enhanced modulus, viscoelastic and rheological properties.

CROSS REFERENCE TO OTHER APPLICATIONS

This application claims the benefit of a U.S. patent application Ser.No. 15/348,249, filed Nov. 10, 2016. U.S. patent application Ser. No.15/348,240 claims the benefit of U.S. Provisional Patent ApplicationSer. No. 62/254,303 filed Nov. 12, 2015. Both applications are herebyincorporated by reference in their entirety.

FIELD

Disclosed is a composite of a fiber and a polymer. The composite hasimproved process characteristics, improved structural product propertiesincluding modulus to produced enhanced products. The novel propertiesare produced in the composite by novel interactions of the fiber andpolymer components.

BACKGROUND

Composite materials have been made for many years by combining generallytwo dis-similar materials to obtain beneficial properties from both. Atrue composite is unique because the interaction of the componentmaterials provides the best properties and characteristics of bothcomponents. Many types of composite materials are known. The use of areinforcing fiber produces a range of materials and, under the correctconditions, can form a true polymer composite. In contrast, a simplefilled polymer, with additive or filler, cannot display compositeproperties. Fillers are often simple replacements for a more expensivecomponent in the composition.

Substantial attention has been paid to the creation of compositematerials with unique properties. Fiber reinforced polymer materialssuch as glass reinforced (GFR) polyvinyl chloride (PVC) have beendeveloped for a variety of end uses. Developing such materials havefaced difficult barriers. In order to obtain significant modulusproperties, a composite needs to maximize the reinforcing fiber loading.Highly filled composite materials cannot be easily made without thermaldepolymerization of the polymer and accompanying hazards of fire andtoxic gasses. In the past the polymers have been stabilized usingadditive materials. Without improved modulus, GFR composites are notfully suited to many demanding structural end uses. Rahrig et al., U.S.Pat. No. 4,801,627 and Kenson et al., U.S. Pat. No. 5,008,145 teachesthat useful GFR is made by combining glass fiber, polyvinyl chloride, areactive coupler and a stabilizer to prevent dehydrohalogenation. Lee etal. U.S. Pat. No. 7,198,840 discloses a profile extruded article made offiber reinforced polymer of vinyl-chloride monomer with amino couplingagents and other additives. Beshay U.S. Pat. No. 5,152,341 disclosescellulose fiber composites. D'Souza US Pat Pub 2005/0238864 disclosesglass bubble composites that can contain some fiber. As a whole, theglass fiber and other fiber composites, while disclosing high fiberloadings, have not been able to achieve much greater than 50 vol. %fiber and are commonly less than 30 vol. % in polymer compositematerials.

While a substantial amount of work has been done regarding fiberreinforced polymer composite materials. A substantial need exists for acomposite material that has improved processing at high fiber loadingsand improved structural properties.

BRIEF DESCRIPTION

A composite of a fiber and a polymer has improved and novel properties.The claimed composite is made of a combination of a thermoplasticpolymer and an interfacial modified fiber (a fiber with a substantiallycomplete coating of an interfacial modifier (IM) with a coatingthickness of less than 1000 Angstroms often less than 200 Angstroms).The composite properties result from a selection of fiber type and size,polymer type, molecular weight, viscoelastic character and processingconditions. The resulting composite materials exceed the contemporarystructural composites in packing, surface inertness, processability andphysical modulus. In the process of making the composite, the fiberinput to the compounding process unit can have an arbitrary length,often about 0.8 to 100 mm. The product output of the compounding processunit can have a fiber of similar length, depending on processconditions. The fiber can be reduced in length if sheared incompounding. The composite containing the fiber can be pelletized. Inthe pellet, the fiber cannot be longer than the major dimension of thepellet. For the purpose of this disclosure the term “fiber” means thefiber (and fiber dimensions) as used as fiber input to the compoundingprocess unit and does not refer to the fiber (and fiber dimensions) inthe resulting compounded composite or to the fiber (and fiberdimensions) in a pelletized composite.

One aspect of the claimed material is a composite of interfaciallymodifier coated fiber and polymer. In this aspect the composite fibercomprises a combination of a cellulosic fiber and a glass fiber. Thecomposite cellulosic fiber can be a wood fiber. The composite comprisesa major proportion of cellulosic fiber and a minor proportion of a glassfiber.

Another aspect is a structural member made of the composite. Suchstructural members can be used in fenestration units including windowsand doors in commercial and residential construction.

Still another aspect is a pellet that can be used as an intermediatebetween the compounding of the composite and the manufacturing of thefinal product. The pellet can be made of the composite and can be formedas the composite is compounded. As the composite is formed and extrudedfrom the compounder the pellet can be cut into pellets useful inthermoplastic part manufacture. Pellets are typically about 2 to 20 mmin length and about 3 to 25 mm in maximum cross sectional dimension. Ina cylindrical pellet the diameter can be about 3 to 20 mm.

A final aspect of the claimed material is a method of compounding thecomposite by compounding the combined polymer resin and interfacialmodified fiber under thermoplastic conditions.

As used in this disclosure the term “fiber” means a fibrous materialinput to a compounding process unit. The fiber material has across-section dimension (preferably but not limited to a diameter) of atleast about 0.8 micron often about 1-150 microns and can be 2-100microns a length of 0.1-150 mm, often 0.2-100 mm, and often 0.3-20 mmand can have an aspect ratio of at least 90 often about 100-1500. Theseaspect ratios are typical if the input is to the compounder. Afterpellets are formed the aspect ratio is set by the pellet dimensions.

Fiber as used in a discontinuous phase can be free of a particle orparticulate.

Particle, or a collection of particles known as a particulate, is adiscrete object having a particle size about 0.1-500 microns, an aspectratio of less than 5 and a circularity ((circularity, is measured by aview of the two dimensional projection of a particle, and is equal to(perimeter)²/area)) is less than 20.

As used in this disclosure the term “continuous phase” means the polymermatrix into which the fiber is dispersed during compounding.

As used in this disclosure the term “discontinuous phase” means the setof individual fibers that are individually dispersed throughout thecontinuous phase.

As used in this disclosure the term as used in this disclosure the term“interfacial modifier” means a material that can coat the surface offiber and does not react with the polymer or other fiber present in thecomposite. In one embodiment the material is an organo-metallicmaterial.

BRIEF DISCUSSION OF THE DRAWINGS

FIG. 1 is a perspective view of an extruded hollow profile structuralmember. Such a member can be used in siding, decking and fenestrationapplications.

FIG. 2 shows a perspective view of an extruded C shaped structuralmember profile.

FIG. 3 shows a perspective view of an extruded I Beam shaped structuralmember profile.

DETAILED DISCUSSION

Novel composites are made by combining an interfacial modified fiber anda polymer to achieve novel physical and process properties.

The fiber is typically coated with an interfacial surface chemicaltreatment also called an interfacial modifier (IM) that supports orenhances the final properties of the composite such as viscoelasticity,rheology, high packing fraction, and fiber surface inertness. Theseproperties are not present in contemporary composite materials.

A composite is more than a simple admixture. A composite is defined as acombination of two or more substances at various percentages, in whicheach component results in properties that are in addition to or superiorto those of its constituents. In a simple admixture the mixed materialhas little interaction and little property enhancement. At least one ofthe materials is chosen to increase stiffness, strength or density. Theatoms and molecules in the components of the composite can form bondswith other atoms or molecules using a number of mechanisms. Such bondingcan occur between the electron cloud of an atom or molecular surfacesincluding molecular-molecular interactions, atom-molecular interactionsand atom-atom interactions. Each bonding mechanism involvescharacteristic forces and dimensions between the atomic centers even inmolecular interactions. The important aspect of such bonding force isstrength, the variation of bonding strength over distance anddirectionality. The major forces in such bonding include ionic bonding,covalent bonding and the van der Waals' (VDW) types of bonding. Ionicradii and bonding occur in ionic species such as Na⁺Cl⁻, Li⁺F⁻. Suchionic species form ionic bonds between the atomic centers. Such bondingis substantial, often substantially greater than 100 kJ-mol⁻¹ oftengreater than 250 kJ-mol⁻¹. Further, the interatomic distance for ionicradii tend to be small and on the order of 1-3 Å. Covalent bondingresults from the overlap of electron clouds surrounding atoms forming adirect covalent bond between atomic centers. The covalent bond strengthsare substantial, are roughly equivalent to ionic bonding and tend tohave somewhat smaller interatomic distances.

The varied types of van der Waals' forces are different than covalentand ionic bonding. These van der Waals' forces tend to be forces betweenmolecules, not between atomic centers. The van der Waals' forces aretypically divided into three types of forces including dipole-dipoleforces, dispersion forces and hydrogen bonding. Dipole-dipole forces area van der Waals' force arising from temporary or permanent variations inthe amount or distribution of charge on a molecule.

TABLE 1 Summary of Chemical Forces and Interactions Strength Type ofInteraction Strength Bond Nature Proportional to: Covalent bond Verystrong Comparatively r⁻¹ long range Ionic bond Very strong Comparativelyr⁻¹ long range Ion-dipole Strong Short range r⁻² VDW Dipole-dipoleModerately Short range r⁻³ strong VDW Ion-induced Weak Very short ranger⁻⁴ dipole VDW Dipole- Very weak Extremely short r⁻⁶ induced dipolerange VDW London Very weak ^(a) Extremely short r⁻⁶ dispersion forcesrange ^(a) Since VDW London forces increase with increasing size andthere is no limit to the size of molecules, these forces can becomerather large. In general, however, they are very weak.

A large variety of polymer and copolymer materials, such asthermoplastic or thermoset polymers, can be used in the compositematerials. We have found that polymer materials useful in the compositeinclude both condensation polymeric materials and addition or vinylpolymeric materials. Vinyl polymers are typically manufactured by thepolymerization of monomers having an ethylenically unsaturated olefinicgroup. Condensation polymers are typically prepared by a condensationpolymerization reaction which is typically considered to be a stepwisechemical reaction in which two or more molecules combined, often but notnecessarily accompanied by the separation of water or some other simple,typically volatile substance. Such polymers can be formed in a processcalled polycondensation. The typical polymer has a density of at least0.85 gm-cm⁻³, however, polymers having a density of greater than 0.96are useful to enhance overall product density. A density is often up to1.7 or up to 2 gm-cm⁻³ or can be about 1.5 to 1.95 gm-cm⁻³.

Vinyl polymers include polyacrylonitrile; polymer of alpha-olefins suchas ethylene, propylene, etc.; polymers of chlorinated monomers such asvinyl chloride, vinylidene chloride, acrylate monomers such as acrylicacid, methyl acrylate, methyl methacrylate, acrylamide, hydroxyethylacrylate, and others; styrenic monomers such as styrene, alpha-methylstyrene, vinyl toluene, etc.; vinyl acetate; and other commonlyavailable ethylenically unsaturated monomer compositions. Examplesinclude polyethylene, polypropylene, polybutylene,acrylonitrile-butadiene-styrene (ABS), polybutylene copolymers,polyacetal resins, polyacrylic resins, homopolymers or copolymerscomprising vinyl chloride, vinylidene chloride, fluorocarbon copolymers,etc.

Condensation polymers include nylon, phenoxy resins, polyarylether suchas polyphenylether, polyphenylsulfide materials; polycarbonatematerials, chlorinated polyether resins, polyethersulfone resins,polyphenylene oxide resins, polysulfone resins, polyimide resins,thermoplastic urethane elastomers and many other resin materials.Condensation polymers that can be used in the composite materialsinclude polyamides, polyamide-imide polymers, polyarylsulfones,polycarbonate, polybutylene terephthalate, polybutylene naphthalate,polyetherimides, polyether sulfones, polyethylene terephthalate,thermoplastic polyamides, polyphenylene ether blends, polyphenylenesulfide, polysulfones, thermoplastic polyurethanes and others. Preferredcondensation engineering polymers include polycarbonate materials,polyphenyleneoxide materials, and polyester materials includingpolyethylene terephthalate, polybutylene terephthalate, polyethylenenaphthalate and polybutylene naphthalate materials.

Polycarbonate engineering polymers are high performance, amorphousengineering thermoplastics having high impact strength, clarity, heatresistance and dimensional stability. Polycarbonates are generallyclassified as a polyester or carbonic acid with organic hydroxylcompounds. The most common polycarbonates are based on phenol A as ahydroxyl compound copolymerized with carbonic acid. Materials are oftenmade by the reaction of a biphenyl A with phosgene (O═CCl₂).Polycarbonates can be made with phthalate monomers introduced into thepolymerization extruder to improve properties such as heat resistance,further trifunctional materials can also be used to increase meltstrength or extrusion blow molded materials. Polycarbonates can often beused as a versatile blending material as a component with othercommercial polymers in the manufacture of alloys. Polycarbonates can becombined with polyethylene terephthalateacrylonitrile-butadiene-styrene, styrene maleic anhydride and others.Preferred alloys comprise a styrene copolymer and a polycarbonate.Preferred polycarbonate materials should have a melt index between 0.5and 7, preferably between 1 and 5 gm./10 min.

A variety of polyester condensation polymer materials includingpolyethylene terephthalate, polybutylene terephthalate, polyethylenenaphthalate, polybutylene naphthalate, etc. can be useful in thecomposites. Polyethylene terephthalate and polybutylene terephthalateare high performance condensation polymer materials. Such polymers oftenmade by a copolymerization between a diol (ethylene glycol, 1,4-butanediol) with dimethyl terephthalate. In the polymerization of thematerial, the polymerization mixture is heated to high temperatureresulting in the transesterification reaction releasing methanol andresulting in the formation of the engineering plastic. Similarly,polyethylene naphthalate and polybutylene naphthalate materials can bemade by copolymerizing as above using as an acid source, a naphthalenedicarboxylic acid. The naphthalate thermoplastics have a higher T_(g)and higher stability at high temperature compared to the terephthalatematerials. However, all these polyester materials are useful in thecomposite materials. Such materials have a preferred molecular weightcharacterized by melt flow properties. Useful polyester materials have aviscosity at 265° C. of about 500-2000 cP, preferably about 800-1300 cP

Polyphenylene oxide materials are engineering thermoplastics that areuseful at temperature ranges as high as 330° C. Polyphenylene oxide hasexcellent mechanical properties, dimensional stability, and dielectriccharacteristics. Commonly, phenylene oxides are manufactured and sold aspolymer alloys or blends when combined with other polymers or fiber.Polyphenylene oxide typically comprises a homopolymer of2,6-dimethyl-1-phenol. The polymer commonly known as poly(oxy-(2,6-dimethyl-1,4-phenylene)). Polyphenylene is often used as analloy or blend with a polyamide, typically nylon 6-6, alloys withpolystyrene or high impact styrene and others. A preferred melt index(ASTM 1238) for the polyphenylene oxide material typically ranges fromabout 1 to 20, preferably about 5 to 10 gm./10 min. The melt viscosityis about 1000 cP at 265° C.

Another class of thermoplastic includes styrenic copolymers. The termstyrenic copolymer indicates that styrene is copolymerized with a secondvinyl monomer resulting in a vinyl polymer. Such materials contain atleast a 5 mol.-% styrene and the balance being 1 or more other vinylmonomers. An important class of these materials is styrene acrylonitrile(SAN) polymers. SAN polymers are random amorphous linear copolymersproduced by copolymerizing styrene acrylonitrile and optionally othermonomers. Emulsion, suspension and continuous mass polymerizationtechniques have been used. SAN copolymers possess transparency,excellent thermal properties, good chemical resistance and hardness.These polymers are also characterized by their rigidity, dimensionalstability and load bearing capability. Olefin modified SAN's (OSApolymer materials) and acrylic styrene acrylonitrile (ASA polymermaterials) are known. These materials are somewhat softer thanunmodified SAN's and are ductile, opaque, two phased terpolymers thathave surprisingly improved weatherability.

ASA polymers are random amorphous terpolymers produced either by masscopolymerization or by graft copolymerization. In mass copolymerization,an acrylic monomer styrene and acrylonitrile are combined to form aheteric terpolymer. In an alternative preparation technique, styreneacrylonitrile oligomers and monomers can be grafted to an acrylicelastomer backbone. Such materials are characterized as outdoorweatherable and UV resistant products that provide excellentaccommodation of color stability property retention and propertystability with exterior exposure. These materials can also be blended oralloyed with a variety of other polymers including polyvinyl chloride,polycarbonate, poly methyl methacrylate and others. An important classof styrene copolymers includes the acrylonitrile-butadiene-styrenemonomers. These polymers are very versatile family of engineeringthermoplastics produced by copolymerizing the three monomers. Eachmonomer provides an important property to the final terpolymer material.The final material has excellent heat resistance, chemical resistanceand surface hardness combined with processability, rigidity andstrength. The polymers are also tough and impact resistant. The styrenecopolymer family of polymers has a melt index that ranges from about 0.5to 25, preferably about 0.5 to 20.

Important classes of engineering polymers that can be used includeacrylic polymers. Acrylics comprise a broad array of polymers andcopolymers in which the major monomeric constituents are an esteracrylate or methacrylate. These polymers are often provided in the formof hard, clear sheet or pellets. Acrylic monomers polymerized by freeradical processes initiated by typically peroxides, azo compounds orradiant energy. Commercial polymer formulations are often provided inwhich a variety of additives are modifiers used during thepolymerization provide a specific set of properties for certainapplications. Pellets made for polymer grade applications are typicallymade either in bulk (continuous solution polymerization), followed byextrusion and pelleting or continuously by polymerization in an extruderin which unconverted monomer is removed under reduced pressure andrecovered for recycling. Using methyl acrylate, methyl methacrylate,higher alkyl acrylates and other copolymerizable vinyl monomers commonlymakes acrylic plastics. Preferred acrylic polymer materials useful inthe composites have a melt index of about 0.5 to 50, preferably about 1to 30 gm./10 min.

Polymer blends or polymer alloys can be useful in manufacturing theclaimed pellet or linear extrudate. Such alloys typically comprise twomiscible polymers blended to form a uniform composition. Scientific andcommercial progress in the area of polymer blends has led to therealization that important physical property improvements can be madenot by developing new polymer material but by forming miscible polymerblends or alloys. A polymer alloy at equilibrium comprises a mixture oftwo amorphous polymers existing as a single phase of intimately mixedsegments of the two macro molecular components. Miscible amorphouspolymers form glasses upon sufficient cooling and a homogeneous ormiscible polymer blend exhibits a single, composition dependent glasstransition temperature (T_(g)). Immiscible or non-alloyed blend ofpolymers typically displays two or more glass transition temperaturesassociated with immiscible polymer phases. In the simplest cases, theproperties of polymer alloys reflect a composition-weighted average ofproperties possessed by the components. In general, however, theproperty dependence on composition varies in a complex way with aparticular property, the nature of the components (glassy, rubbery orsemi-crystalline), the thermodynamic state of the blend, and itsmechanical state whether molecules and phases are oriented.

The primary requirement for the substantially thermoplastic engineeringpolymer material is that it retains sufficient thermoplastic propertiessuch as viscosity and stability, to permit melt blending with a fiber,permit formation of linear extrudate pellets, and to permit thecomposition material or pellet to be extruded or injection molded in aconventional thermoplastic process forming the useful product.Engineering polymer and polymer alloys are available from a number ofmanufacturers including Dyneon LLC, B.F. Goodrich, G.E., Dow, andduPont.

Polyester polymers are manufactured by the reaction of a dibasic acidwith a glycol. Dibasic acids used in polyester production includephthalic anhydride, isophthalic acid, maleic acid and adipic acid. Thephthalic acid provides stiffness, hardness and temperature resistance;maleic acid provides vinyl saturation to accommodate free radical cure;and adipic acid provides flexibility and ductility to the cured polymer.Commonly used glycols are propylene glycol, which reduces crystallinetendencies and improves solubility in styrene. Ethylene glycol anddiethylene glycol reduce crystallization tendencies. The diacids andglycols are condensed eliminating water and are then dissolved in avinyl monomer to a suitable viscosity. Vinyl monomers include styrene,vinyl toluene, para methyl styrene, methyl methacrylate, and diallylphthalate. The addition of a polymerization initiator, such ashydroquinone, tertiary butyl catechol or phenothiazine extends the shelflife of the uncured polyester polymer. Polymers based on phthalicanhydride are termed ortho phthalic polyesters and polymers based onisophthalic acid are termed isophthalic polyesters. The viscosity of theunsaturated polyester polymer can be tailored to an application. Lowviscosity is important in the fabrication of fiber-reinforced compositesto ensure good wetting and subsequent high adhesion of the reinforcinglayer to the underlying substrate. Poor wetting can result in largelosses of mechanical properties. Typically, polyesters are manufacturedwith a styrene concentration or other monomer concentration producingpolymer having an uncured viscosity of 200-1,000 mPa·s (cP). Specialtypolymers may have a viscosity that ranges from about 20 cP to 2,000 cP.Free radical initiators commonly produced using peroxide materials totypically cure unsaturated polyester polymers. Wide varieties ofperoxide initiators are available and are commonly used. The peroxideinitiators thermally decompose forming free radical initiating species.

The fluorocarbon polymers are per-fluorinated and partially fluorinatedpolymers made with monomers containing one or more atoms of fluorine, orcopolymers of two or more of such monomers. Common examples ofthermoplastic fluorinated monomers useful in these polymers orcopolymers include hexafluoropropylene (HFP), vinylidene fluoride (VDF),perfluoroalkylvinyl ethers such as perfluoro-(n-propyl-vinyl) ether(PPVE) or perfluoromethylvinylether (PMVE). Other copolymerizableolefinic monomers, including non-fluorinated monomers, may also bepresent.

Particularly useful materials for the fluorocarbon polymers areTFE-HFP-VDF terpolymers (melting temperature of about 100 to 260° C.;melt flow index at 265° C. under a 5 kg load is about 1-30 g-10hexafluoropropylene-tetrafluoroethylene-ethylene (HTE) terpolymers(melting temperature about 150 to 280° C.; melt flow index at 297° C.under a 5 kg load of about 1-30 g-10 min⁻¹.),ethylene-tetrafluoroethylene (ETFE) copolymers (melting temperatureabout 250 to 275° C.; melt flow index at 297° C. under a 5 kg load ofabout 1-30 g-10 min⁻¹.), hexafluoropropylene-tetrafluoroethylene (FEP)copolymers (melting temperature about 250 to 275° C.; melt flow index at372° C. under a 5 kg load of about 1-30 g-10 min⁻¹.), andtetrafluoroethylene-perfluoro(alkoxy alkane) (PFA) copolymers (meltingtemperature about 300 to 320° C.; melt flow index at 372° C. under a 5kg load of about 1-30 g-10 min⁻¹.). Each of these fluoropolymers iscommercially available from Dyneon LLC, Oakdale, Minn. The TFE-HFP-VDFterpolymers are sold under the designation “THV”.

Also useful are vinylidene fluoride polymers primarily made up ofmonomers of vinylidene fluoride, including both homo polymers andcopolymers. Such copolymers include those containing at least 50 molepercent of vinylidene fluoride copolymerized with at least one comonomerselected from the group consisting of trifluoroethylene,chlorotrifluoroethylene, hexafluoropropene, vinyl fluoride,pentafluoropropene, and any other monomer that readily copolymerizeswith vinylidene fluoride. These materials are further described in U.S.Pat. No. 4,569,978 (Barber) incorporated herein by reference. Preferredcopolymers are those composed of from at least about 70 and up to 99mole percent vinylidene fluoride, and correspondingly from about 1 to 30percent tetrafluoroethylene, such as disclosed in British Patent No.827,308; and about 70 to 99 percent vinylidene fluoride and 1 to 30percent hexafluoropropene (see for example U.S. Pat. No. 3,178,399); andabout 70 to 99 mole percent vinylidene fluoride and 1 to 30 percenttrifluoroethylene. Terpolymers of vinylidene fluoride, trifluoroethyleneand tetrafluoroethylene such as described in U.S. Pat. No. 2,968,649 andterpolymers of vinylidene fluoride, trifluoroethylene andtetrafluoroethylene are also representative of the class of vinylidenefluoride copolymers. Such materials are commercially available under theKYNAR trademark from Arkema Group located in King of Prussia, Pa. orunder the DYNEON trademark from Dyneon LLC of Oakdale, Minn.

Fluorocarbon elastomer materials can also be used in the compositematerials. Fluorocarbon elastomers contain VF₂ and HFP monomers andoptionally TFE and have a density greater than 1.8 gm-cm⁻³. Thesepolymers exhibit good resistance to most oils, chemicals, solvents, andhalogenated hydrocarbons, and excellent resistance to ozone, oxygen, andweathering. Their useful application temperature range is −40° C. to300° C. Fluorocarbon elastomer examples include those described indetail in Lentz, U.S. Pat. No. 4,257,699, as well as those described inEddy et al., U.S. Pat. No. 5,017,432 and Ferguson et al., U.S. Pat. No.5,061,965. The disclosures of each of these patents are totallyincorporated herein by reference.

Useful vinyl chloride polymers used in preparing the compositionsinclude the homopolymer of vinyl chloride, i.e. polyvinyl chloride, andcopolymers of vinyl chloride with mono-ethylenically unsaturatedmonomers wherein the copolymer contains at least about 80 percent of thevinyl chloride units. The materials to be copolymerized with vinylchloride include, but are not restricted to vinyl acetate, vinylidenechloride, diethyl fumarate, methyl methacrylate, meth acrylonitrile,acrylonitrile, styrene, allyl alcohol, ethyl vinyl succinate, allylethyl phthalate, vinyl benzoate, allyl acetate, and the like andmixtures thereof. Particularly preferred starting materials comprisepolyvinyl chloride and copolymers thereof, vinyl chloride withethylenically unsaturated esters, vinylidene chloride with styrene andacrylonitrile.

Useful fiber includes both natural and synthetic fibers. Natural fiberincludes those of animal or plant origin. Plant based examples includecellulosic materials such as wood fiber, cotton, flax, jute, celluloseacetate etc.; animal based materials made of protein include wool, silketc. Synthetic fibers include polymer materials such as acrylic, aramid,amide-imide, nylon, polyolefin, polyester, polyurethane, carbon, etc.Other types include glass, metal, or ceramic fibers. Metallic fibers aremanufactured fibers of metal, metal coated plastic or a core completelycovered by metal. Non-limiting examples of such metal fibers includegold, silver, aluminum, stainless steel and copper. The metal fibers maybe used alone or in combinations. The determinant for the selectionmetal fiber is dependent on the properties desired in the compositematerial or the shaped article made therefrom. One useful fibercomprises a glass fiber known by the designations: A, C, D, E, ZeroBoron E, ECR, AR, R, S, S-2, N, and the like. Generally, any glass thatcan be made into fibers either by drawing processes used for makingreinforcement fibers or spinning processes used for making thermalinsulation fibers. Such fiber is typically used as a length of about0.8-100 mm often about 2-100 mm, a diameter about 0.8-100 microns and anaspect ratio (length divided by diameter) greater than 90 or about 100to 1500. These commercially available fibers are often combined with asizing coating. Such coatings cause the otherwise ionically neutralglass fibers to form and remain in bundles or fiber aggregates. Sizingcoatings are applied during manufacture before gathering. The sizingminimizes filament degradation caused by filament to filament abrasion.Sizings can be lubricants, protective, or reactive couplers but do notcontribute to the properties of a composite using an interfacialmodifier coating on the fiber surface.

Dipole structures arise by the separation of charges on a moleculecreating a generally or partially positive and a generally or partiallynegative opposite end. The forces arise from electrostatic interactionbetween the molecule negative and positive regions. Hydrogen bonding isa dipole-dipole interaction between a hydrogen atom and anelectronegative region in a molecule, typically comprising oxygen,fluorine, nitrogen or other relatively electronegative (compared to H)site. These atoms attain a dipole negative charge attracting adipole-dipole interaction with a hydrogen atom having a positive charge.Dispersion force is the van der Waals' force existing betweensubstantially non-polar uncharged molecules. While this force occurs innon-polar molecules, the force arises from the movement of electronswithin the molecule. Because of the rapidity of motion within theelectron cloud, the non-polar molecule attains a small but meaningfulinstantaneous charge as electron movement causes a temporary change inthe polarization of the molecule. These minor fluctuations in chargeresult in the dispersion portion of the van der Waals' force.

Such VDW forces, because of the nature of the dipole or the fluctuatingpolarization of the molecule, tend to be low in bond strength, typically50 kJ mol⁻¹ or less. Further, the range at which the force becomesattractive is also substantially greater than ionic or covalent bondingand tends to be about 3-10 Å.

In the van der Waals composite materials, we have found that the uniquecombination of fiber, the varying but controlled size and aspect ratioof the fiber component, the modification of the interaction between thefiber and the polymer, result in the creation of a unique van der Waals'bonding. The van der Waals' forces arise between atoms/crystals and arecreated by the combination of fiber size, polymer and interfacialmodifiers in the composite.

In the past, materials that are characterized, as “composite” havemerely comprised a polymer filled with particulate with little or no vander Waals' interaction between the particulate filler material. Theinteraction between the selection of fiber size distribution andinterfacially modified fiber enables the fiber to achieve anintermolecular distance that creates a substantial van der Waals' bondstrength. The prior art materials having little viscoelastic properties,do not achieve a true composite structure. This leads us to concludethat this intermolecular distance is not attained in the prior art. Inthe discussion above, the term “molecule” can be used to relate to afiber, a fiber comprising non-metal crystal or an amorphous aggregate,other molecular or atomic units or sub-units of non-metal or inorganicmixtures. The van der Waals' forces occur between collections of metalatoms, embodiments of the interfacial modifier, that act as “molecules”.

The is characterized by a composite having intermolecular forces betweenfibers about 30 kJ-mol⁻¹ and a bond dimension of 3-10 Å. The fiber inthe composite, the reinforcement, is usually much stronger and stifferthan the matrix, and gives the composite its good properties in, forexample a shaped article, structural member or other end use. The matrixholds the reinforcements in an orderly high-density pattern. Because thereinforcements are usually discontinuous, the matrix also helps totransfer load among the reinforcements. Processing can aid in the mixingand filling of the reinforcement or fiber. To aid in the mixture, aninterfacial modifier can help to overcome the forces that prevent thematrix from forming a substantially continuous phase of the composite.The composite properties arise from the intimate association ofinterfacially modified fiber and polymer obtained by use of carefulprocessing and manufacture.

An interfacial modifier is an organo-metallic material that provides anexterior coating on the fiber promoting the close association, but notattachment or bonding, of polymer to fiber and fiber to fiber. Thecomposite properties arise from the intimate association of the polymerand fiber obtained by use of careful processing and manufacture. Aninterfacial modifier is an organic material, in some examples anorgano-metallic material, that provides an exterior coating on the fiberto provide a surface that can associate with the polymer promoting theclose association of polymer and fiber but with no reactive bonding,such as covalent bonding for example, of polymer to fiber, fiber tofiber, or fiber to a different particulate, such as a glass fiber or aglass bubble. The lack of reactive bonding between the components of thecomposite leads to the formation of the novel composite—such as highpacking fraction, commercially useful rheology, viscoelastic properties,and surface inertness of the fiber. These characteristics can be readilyobserved when the composite with interfacially modified coated fiber iscompared to fiber lacking the interfacial modifier coating. In oneembodiment, the coating of interfacial modifier at least partiallycovers the surface of the fiber. In another embodiment, the coating ofinterfacial modifier continuously and uniformly covers the surface ofthe fiber, in a continuous coating phase layer. Minimal amounts of themodifier can be used including about 0.005 to 8 wt.-%, about 0.02 to6.0, wt. %, about 0.02 to 3.0 wt. %, about 0.02 to 4.0 wt. % or about0.02 to 5.0 wt. %.

Interfacial modifiers used in the application fall into broad categoriesincluding, for example, titanate compounds, zirconate compounds, hafniumcompounds, samarium compounds, strontium compounds, neodymium compounds,yttrium compounds, phosphonate compounds, aluminate compounds and zinccompounds. Aluminates, phosphonates, titanates and zirconates that areuseful contain from about 1 to about 3 ligands comprising hydrocarbylphosphate esters and/or hydrocarbyl sulfonate esters and about 1 to 3hydrocarbyl ligands which may further contain unsaturation andheteroatoms such as oxygen, nitrogen and sulfur. In embodiments thetitanates and zirconates contain from about 2 to about 3 ligandscomprising hydrocarbyl phosphate esters and/or hydrocarbyl sulfonateesters, preferably 3 of such ligands and about 1 to 2 hydrocarbylligands, preferably 1 hydrocarbyl ligand.

In one embodiment the interfacial modifier that can be used is a type oforgano-metallic material such as organo-cobalt, organo-iron,organo-nickel, organo-titanate, organo-aluminate organo-strontium,organo-neodymium, organo-yttrium, organo-zinc or organo-zirconate. Thespecific type of organo-titanate, organo-aluminates, organo-strontium,organo-neodymium, organo-yttrium, organo-zirconates which can be usedand which be referred to as organo-metallic compounds are distinguishedby the presence of at least one hydrolysable group and at least oneorganic moiety. Mixtures of the organo-metallic materials may be used.The mixture of the interfacial modifiers may be applied inter- orintra-fiber, which means at least one fiber may has more than oneinterfacial modifier coating the surface (intra), or more than oneinterfacial modifier coating may be applied to different fibers or fibersize distributions (inter). Certain of these types of compounds may bedefined by the following general formula:M(R₁)_(n)(R₂)_(m)wherein M is a central atom selected from such metals as, for example,Ti, Al, and Zr and other metal centers; R₁ is a hydrolysable group; R₂is a group consisting of an organic moiety, preferably an organic groupthat is non-reactive with polymer or other film former; wherein the sumof m+n must equal the coordination number of the central atom and wheren is an integer ≥1 and m is an integer ≥1.

Particularly R₁ is an alkoxy group having less than 12 C atoms. Otheruseful groups are those alkoxy groups, which have less than 6 C, andalkoxy groups having 1-3 C atoms. R₂ is an organic group includingbetween 6-30, preferably 10-24 carbon atoms optionally including one ormore hetero atoms selected from the group consisting of N, O, S and P.R₂ is a group consisting of an organic moiety, which is not easilyhydrolyzed and is often lipophilic and can be a chain of an alkyl,ether, ester, phospho-alkyl, phospho-alkyl, phospho-lipid, orphospho-amine. The phosphorus may be present as phosphate,pyrophosphato, or phosphito groups. Furthermore, R₂ may be linear,branched, cyclic, or aromatic. R₂ is substantially unreactive, i.e. notproviding attachment or bonding, to other particles or fiber within thecomposite material.

The use of an interfacial modifier results in workable thermoplasticviscosity and improved structural properties in a final use such as astructural member or shaped article. Minimal amounts of the modifier canbe used including about 0.005 to 8 wt.-%, about 0.01 to 6 wt.-%, about0.02 to 5 wt.-%, or about 0.02 to 3 wt. %. The IM coating can be formedas a coating of at least 3 molecular layers or at least about 50 orabout 100 to 500 or about 100 to 1000 angstroms (Å). The claimedcomposites with increased loadings of fiber can be safely compounded andthermoplastically formed into high strength structural members. Theinterfacial modification technology depends on the ability to isolatethe fibers from continuous polymer phase. The isolation is obtained froma continuous molecular layer(s) of interfacial modifier to bedistributed over the fiber surface. Once this layer is applied, thebehavior at the interface of the interfacial modifier to polymerdominates and defines the physical properties of the composite and theshaped or structural article (e.g. modulus, tensile, rheology, packingfraction and elongation behavior) while the bulk nature of the fiberdominates the bulk material characteristics of the composite (e.g.density, thermal conductivity, compressive strength). The correlation offiber bulk properties to that of the final composite is especiallystrong due to the high volume percentage loadings of discontinuousphase, such as fiber, associated with the technology.

There are two key attributes of the surface coating that dictate theability to be successfully interfacially modified: 1) the overallsurface area of fiber; and 2) fiber surface characteristics that are onthe order of the molecular size of the interfacial modifier beingapplied.

Sizing materials used as glass coatings do not act as interfacialmodifiers. Sizing is an essential in glass fiber manufacture andcritical to certain glass fiber characteristics determining how fiberswill be handled during manufacturing and use. Raw fibers are abrasiveand easily abraded and reduced in size. Without sizing, fibers can bereduced to useless “fuzz” during processing. Sizing formulations havebeen used by manufacturers to distinguish their glass products fromcompetitors' glass products. Glass fiber sizing, typically, is a mixtureof several chemistries each contributing to sizing performance on theglass fiber surface. Sizings typically are manufactured from filmforming compositions and reactive coupling agents. Once formed, thecombination of a film forming material and a reactive coupler forms areactively coupled film that is, reactively coupled to the glass fibersurface. The sizing protects the fiber, holding fibers together prior tomolding but promote dispersion of the fiber when coming into contactwith polymer or resin insuring wet out of glass fiber with resin duringcomposite manufacture. Typically, the coupling agent used with the filmforming agent, is a reactive alkoxy silane compound serving primarily tobond the glass fiber to their matrix or film forming resin. Silanetypically have a silicon containing group and that bonds well to glass(typically SiO₂) with a reactive organic end that bonds well to filmforming polymer resins. Sizings also may contain additional lubricatingagents as well as anti-static agents. We have used sized fibers in ourstudies and found that sizing does not act as interfacial modifier andwe can coat all sizing that we have found.

Aspect Ratio

The benefit of interfacial modification on a fully coated fiber isindependent of overall fiber shape. The current upper limit constraintis associated with challenges of successful dispersion of fibers withinlaboratory compounding equipment without significantly damaging the highaspect ratio fibers. Furthermore, inherent rheological challenges areassociated with high aspect ratio fibers. With proper engineering, theability to successfully compound and produce interfacially modify fibersof fiber fragments with aspect ratio in excess of 20 often in excess of100, 200 or more is provided.

For composites containing high volumetric loading of fibers, therheological behavior of the highly packed composites depends on thecharacteristics of the contact points between the fibers and thedistance between fibers. When forming composites with polymeric volumesapproximately equal to the excluded volume of the discontinuous phase,inter-fiber interaction dominates the behavior of the material. Fiberscontact one another and the combination of interacting sharp edges, softsurfaces (resulting in gouging) and the friction between the surfacesprevent further or optimal packing. Interfacial modifying chemistriesare capable of altering the surface of the fiber by coordinationbonding, Van der Waals forces, or a combination of all three. Thesurface of the interfacially modified fiber behaves as a fiber formed ofthe non-reacted end or non-reacting end of the interfacial modifier. Thecoating of the interfacial modifier improves particle wetting by thepolymer and as a result improves the physical association of the fiberand polymer in the formed composite leading to improved physicalproperties including, but not limited to, increased tensile and flexuralstrength, increased tensile and flexural modulus, improved notched IZODimpact and reduced coefficient of thermal expansion. In the melt, theinterfacial modified coating on the fiber reduces the friction betweenfibers thereby preventing gouging and allowing for greater freedom ofmovement between fibers in contrast to fibers that have not been coatedwith interfacial modifier chemistry. As a result, the composite can bethermoplastically processed at greater productivity and at conditions ofreduced temperature and pressure severity. The process and physicalproperty benefits of utilizing the coated fibers in the aforementionedacceptable fiber morphology index range does not become evident untilpacking to a significant proportion of the maximum packing fraction;this value is typically greater than approximately 40, 50, 60, 70, 80,90, 92 or 95 volume or weight % of the fiber phase in the composite.

In a composite, the fiber is usually much stronger and stiffer than thepolymer matrix, and gives the composite its designed structural orshaped article properties. The matrix holds the fiber in an orderlyhigh-density pattern. Because the fibers are usually discontinuous, thematrix also helps to transfer load among the non-metal, inorganic,synthetic, natural, or mineral fibers. Processing can aid in the mixingand filling of the non-metal, inorganic or mineral fibers. To aid in themixture, an interfacial modifier can help to overcome the forces thatprevent the matrix from forming a substantially continuous phase of thecomposite. The tunable composite properties arise from the intimateassociation of the fiber and the polymer obtained by the use of carefulpolymer processing and manufacture. We believe an interfacial modifier(IM) is an organic material that provides an exterior coating on thefiber promoting the close association of polymer and fiber. Minimalamounts of the interfacial modifier can be used including about 0.005 to8 wt.-%, 0.01 to 6 wt. % or about 0.02 to 3 wt. %. Higher amounts of theIM are used to coat materials with increased surface morphology.

Typically, the composite materials can be manufactured using meltprocessing and are also utilized in product formation using meltprocessing. A typical thermoplastic polymer material, is combined withfiber and processed until the material attains (e.g.) a uniform density(if density is the characteristic used as a determinant). Alternatively,in the manufacture of the material, the fiber or the thermoplasticpolymer may be blended with interfacial modification agents and themodified materials can then be melt processed into the material. Oncethe material attains a sufficient property, such as, for example,density, the material can be extruded into a product or into a rawmaterial in the form of a pellet, chip, wafer, preform or other easilyprocessed material using conventional processing techniques.

In the manufacture of useful products, the manufactured composite can beobtained in appropriate amounts, subjected to heat and pressure,typically in extruder useful for 3D printing (additive manufacturing),or injection molding equipment and then formed into an appropriate shapehaving the correct amount of materials in the appropriate physicalconfiguration. In the appropriate product design, during compositemanufacture or during product or article manufacture, a pigment or otherdye material can be added to the processing equipment. One advantage ofthis material is that an inorganic dye or pigment can be co-processedresulting in a material that needs no exterior painting or coating toobtain an attractive, functional, or decorative appearance. The pigmentscan be included in the polymer blend, can be uniformly distributedthroughout the material and can result in a surface that cannot chip,scar or lose its decorative appearance. One particularly importantpigment material comprises titanium dioxide (TiO₂). This material isextremely non-toxic, is a bright white particulate that can be easilycombined with the fiber and/or polymer composites to enhance the novelcharacteristics of the composite material and to provide a white hue tothe ultimate composite material.

The manufacture of the composite materials depends on good manufacturingtechnique. The fiber is initially treated with an interfacial modifierby contacting the fiber with the modifier in the form of a solution ofinterfacial modifier on the fiber with blending and drying carefully toensure uniform particulate or fiber coating. Interfacial modifier canalso be added to fibers in bulk blending operations using high intensityLittleford or Henschel blenders. Alternatively, twin cone mixers can befollowed by drying or direct addition to a screw compounding device.Interfacial modifiers may also be reacted with the particulate inaprotic solvent such as toluene, tetrahydrofuran, mineral spirits orother such known solvents.

The particulate can be combined into the polymer phase depending on thenature of the polymer phase, the filler, the particulate surfacechemistry and any pigment process aid or additive present in thecomposite material. Titanates provide antioxidant properties and canmodify or control cure chemistry. A useful titanate material is2-propanolato, tris isooctadecanoato-O-titanium IV, an isopropyltriisostearoyl titanate. Zirconate provides excellent coating andreduces formation of off color in formulated thermoplastic materials. Auseful zirconate material is neopentyl (diallyl) oxy-tri (dioctyl)phosphato-zirconate.

The composite materials having the desired physical properties can bemanufactured as follows. In an embodiment, the surface of the fiber isinitially prepared, the interfacial modifier coats the fiber, and theresulting product is isolated and then combined with the continuouspolymer phase to affect an immiscible dispersion or association betweenthe fiber and the polymer. Once the composite material is compounded orprepared, it is then thermoplastically formed into the desired shape ofthe end use article. Solution processing is an alternative that providessolvent recovery during materials processing. The materials can also bedry-blended without solvent. Blending systems such as ribbon blendersobtained from Drais Systems, high-density drive blenders available fromLittleford Brothers and Henschel are possible. Further melt blendingusing Banberry, other single screw or twin screw compounders is alsouseful. When the materials are processed as a plastisol or organosolwith solvent, liquid ingredients are generally charged to a processingunit first, followed by polymer, particulate and rapid agitation. Onceall materials are added a vacuum can be applied to remove residual airand solvent, and mixing is continued until the product is uniform andhigh in density.

Dry blending is generally preferred due to advantages in cost. Howevercertain embodiments can be compositionally unstable due to differencesin fiber size. In dry blending processes, the composite can be made byfirst introducing the polymer, combining the polymer stabilizers, ifnecessary, at a temperature from about ambient to about 60° C. with thepolymer, blending a particulate (modified if necessary) with thestabilized polymer, blending other process aids, interfacial modifier,colorants, indicators or lubricants followed by mixing in hot mix,transfer to storage, packaging or end use manufacture.

Interfacially modified materials can be made with solvent techniquesthat use an effective amount of solvent to initiate formation of acomposite. When interfacial treatment is substantially complete, thesolvent can be stripped. With an IM the composites can achieve thefollowing properties:

TABLE 2 ASTM Minimum Range of Property Method Value Value Units TensileD638 35 (5 × 10⁴) >35 MPa (psi) Strength Tensile D638  8 (1.2 × 10⁶) >4GPa (psi) Modulus Flexural D790 35 (5 × 10⁴) >35 MPa (psi) StrengthFlexural D790  8 (1.2 × 10⁶) >4 GPa (psi) Modulus Notched D256 70(1.3) >30 J/m (ft IZOD lbs/in) COTE D969 Maximum Value: <5.4 × 10⁻⁵cm/cm/° C. 1.9 × 10⁻⁵ (1.1 × 10⁻⁵) in/in/° F.Additional, the use of the IM permits an increase in the fiber loadingin the composite. As the fiber content increases, the polymer contentdecreases. The thermal expansion of a structural member made with thedisclosed material will be improved as fiber content increases, e.g.,the material will have reduced coefficient of thermal expansion (COTE).

EXPERIMENTAL SECTION Example 1

The glass fiber (Pittsburgh Plate Glass (Pittsburgh, Pa.)) is firsttreated with an interfacial modifier titanium IV 2-propanolato, trisisooctadecanoato-O (commercially available as KR®TTS from Kenrich). Thisis done by dissolving the desired amount of the interfacial modifier ina 250 ml beaker containing 50 ml of solvent (usually isopropyl, or someother, alcohol). The resulting slurry is then heated to an appropriatetemperature such as 65-100° C. until the mixture can no longer bestirred and most of the solvent has been driven off. The beakercontaining the glass fiber with interfacial modifier is then placed inan oven for drying at a time and temperature, such as 30 minutes at 100°C. The treated mixed particulate is then added to a 100 ml beakercontaining a solution of a polymer such as THV220A dissolved in acetone.THV220A is a thermoplastic fluoropolymer of tetrafluoroethylene,hexafluoropropylene, and vinylidene fluoride available from 3M (St.Paul, Minn.). Other polymers for example PLA and PVC may also be usefuldepending on the function and structure of the final article or shape.The mixture is then heated to a temperature, such as, to 30° C. andcontinuously stirred until most of the acetone has evaporated. Thecomposite material is then placed in a forced air oven for a time suchas, 30 minutes at 100° C.

After compounding, the composite material is extruded with a 1 inchextruder and tested for various material properties. The composite has aflex modulus as measured by ASTM D790 at 77° F. (25° C.), tensilemodulus as measured by ASTM D638 at 77° F. (25° C.) and a notched Izodas measured by ASTM D256 at 77° F. (25° C.) and a viscosity/torque in aBrabender mixer as measured by an appropriate ASTM protocol.

Example 2

A series of composites are made having 35-55 wt. % polyvinyl chlorideand 45-65 wt. % glass fiber. The glass fiber from, for example,Pittsburgh Plate Glass (Pittsburgh, Pa.) is first treated with aninterfacial modifier such as titanium IV 2-propanolato, trisisooctadecanoato-O (commercially available as Kenrich KR®TTS). This isdone by placing 100 grams of the glass fiber into the beaker and thenthe desired amount of the interfacial modifier into the same beaker. Theresulting mixture is then heated to an appropriate temperature such as65-100° C. until the mixture is homogeneous.

The treated fiber is then added to another beaker containing anappropriate amount of polymer, for example, Geon™ Vinyl 87180. Geon™Vinyl 87180 is a polymer consisting of vinyl chloride monomers availablefrom PolyOne Corporation (Avon Lake, Ohio). Other polymers, such as ABS,may also be useful depending on the function and structural of the finalarticle or shape. The mixture is then added to a twin screw extruderheated to a temperature, such as, to 195° C. and compounded.

After compounding, the composite material is extruded with a 1 inchextruder and tested for various material properties. The composite has aflex modulus as measured by ASTM D790 at 77° F. (25° C.), tensilemodulus as measured by ASTM D638 at 77° F. (25° C.) and a notched Izodas measured by ASTM D256 at 77° F. (25° C.) and a viscosity/torque in aBrabender mixer as measured by an appropriate ASTM protocol.

Example 3

A series of composites are made having 30-50 wt. % AcrylonitrileButadiene Styrene (ABS) polymer and 50-70 wt. % glass fiber. The fiberis first treated with an interfacial modifier such as titanium IV2-propanolato, tris isooctadecanoato-O (commercially available asKenrich KR®TTS). A 100-gram portion of the glass fiber is placed into abeaker with the desired amount of the interfacial modifier and preparedas in Examples 1 or 2.

The treated fiber is then added to another beaker containing anappropriate amount of polymer, Lustran® ABS 433. Lustran® ABS 433 is ageneral-purpose injection-molding grade of ABS (Acrylonitrile ButadieneStyrene). It is a high impact, high-gloss ABS. The mixture is then addedto a twin screw extruder heated to a temperature, such as to 195° C. andcompounded.

After compounding, the composite material is extruded with a 1 inchextruder and tested for various material properties. The composite has aflex modulus as measured by ASTM D790 at 77° F. (25° C.), tensilemodulus as measured by ASTM D638 at 77° F. (25° C.) and a notched Izodas measured by ASTM D256 at 77° F. (25° C.) and a viscosity/torque in aBrabender mixer as measured by an appropriate ASTM protocol.

The data shows that the fiber polymer composites as claimed haveenhanced properties of the composite such as processability,viscoelasticity, rheology, high packing fraction, and fiber surfaceinertness.

TABLE 3 Interfacial Coated Coated Coated Polymer Modifier Fiber FiberFiber Composite Density Wt. Vol. Wt. Vol. Density Wt. Vol. Density ExPolymer (g/cc) % % pph % % (g/cc) % % (g/cc) 4 ABS* 1.0478 48.41 70 1.50.76 1.15 2.605 51.58 30.00 1.515 5 CPVC 1.4826 57.04 70 1.5 0.63 1.152.605 42.95 30.00 1.8194 (powder)* *These material values had adifferent (older) sample prep method as well as modulus calculation.

TABLE 4 Tensile Tensile Flexural Flexural Strength Modulus StrengthModulus Composite (Mpa) (GPa) (MPa) (GPa) Density ASTM ASTM ASTM ASTM EX(g/cc) D3039 D3039 D790 D790 4 1.515 23.7 6.4 66.1 10.3 5 1.8194 29.68.4 66.0 11.5

Table 3 shows polymer fiber composites of the invention made in examples3 and 4 and being made from acrylonitrile-butadiene-styrene (ABS) andchlorinated poly vinyl chloride (CPVC) and glass fiber coated withinterfacial modifier (IM). Table 4 shows that the manufacturedcomposites have suitable and acceptable physical characteristics asshown by ASTM testing for tensile strength, tensile modulus, flexuralstrength and flexural modulus.

Useful volume % of the fiber phase in the composite of the invention canbe adjusted to above 40, 50, 60, 70, 80, or 90%, depending on the enduse of the article or structural member and the required physicalproperties of the article or structural member, without loss ofprocessability, viscoelasticity, rheology, high packing fraction, andfiber surface inertness of the composite.

Methods and Procedures

Application of Interfacial Modifier:

To interfacially modify at a lab scale, the interfacial modifier isfirst solubilized with a solvent such as IPA. The solvent/modifiermixture is applied to a fiber portion previously placed within apreparation vessel. The solvent/modifier mixture is added in enoughvolume to fully wet and flood the fiber. The outer part of vessel isthen heated to volatize the solvent. After a sufficient time, themodified fiber becomes free flowing—an indication that they are readyfor compounding and thermoplastic processing. The extruded or injectionmolded member can be formed as a linear member or a hollow profile.

The improved process viscosity can be seen in comparing the processingof a composite as claimed compared to a composite of uncoated fiber. Theclaimed materials have substantially reduced processing viscosity thatis derived from the freedom of movement of the interfacially modifiedfiber within the polymer matrix. The IM also provides some fiberself-ordering which increases fiber packing fraction without the loss ofrheology or breakage of fibers. We used a C. W. Brabender ComputerizedPlasti-Corder test mixer equipped with a 19.1 mm. (¾ in.) diameterextruder with a 25/1 length/diameter ratio. The extrusion screw had tenfeed flights, 10 compression flights with a compression ratio of 3:1,and 5 metering flights. Operating parameters were controlled by 5independent heating zones, four pressure transducers and atorque-measuring drive unit. Software module was used for extrusiondata. The capillary die, made from #416 stainless steel, had a diameterof 2 mm and a length of 40 mm. In operation, the operating conditionswere set and the fiber polymer composite was then extruded untilequilibrium (constant throughput and constant die pressure) werereached. Extrusion at 40 rpm and a die pressure of about 28 Mpa wereused. Brabender viscosity is reported as torque according to theappropriate ASTM protocol in N-m. The linear member can be in the formof dimensioned lumber, trim pieces, circular cross-section rod, I-beam,etc. The profile comprises an exterior wall or shell substantiallyenclosing a hollow interior. The interior can contain structural webproviding support for the walls and can contain one fastener anchor.

The interior of the structural member is commonly provided with one ormore structural webs which in a direction of applied stress supports thestructure. Structural web typically comprises a wall, post, supportmember, or other formed structural element which increases compressivestrength, torsion strength, or other structural or mechanicalproperties. Such structural web connects the adjacent or opposingsurfaces of the interior of the structural member. More than onestructural web can be placed to carry stress from surface to surface atthe locations of the application of stress to protect the structuralmember from crushing, torsional failure or general breakage. Typically,such support webs are extruded or injection molded during themanufacture of the structural material. However, a support can be postadded from parts made during separate manufacturing operations.

The internal space of the structural member can also contain a fasteneranchor or fastener installation support. Such an anchor or support meansprovides a locus for the introduction of a screw, nail, bolt or otherfastener used in either assembling the unit or anchoring the unit to arough opening in the commercial or residential structure. The anchor webtypically is conformed to adapt itself to the geometry of the anchor andcan simply comprise an angular opening in a formed composite structure,can comprise opposing surfaces having a gap or valley approximatelyequal to the screw thickness, can be geometrically formed to match a keyor other lock mechanism, or can take the form of any commonly availableautomatic fastener means available to the window manufacturer fromfastener or anchor parts manufactured by companies such as AmerockCorp., Illinois Tool Works and others.

The structural member can have premolded paths or paths machined intothe molded thermoplastic composite for passage of door or window units,fasteners such as screws, nails, etc. Such paths can be counter sunk,metal lined, or otherwise adapted to the geometry or the composition ofthe fastener materials. The structural member can have mating surfacespremolded in order to provide rapid assembly with other window.Components of similar or different compositions having similarly adaptedmating surfaces. Further, the structural member can have mating surfacesformed in the shell of the structural member adapted to moveable windowsash or door sash or other moveable parts used in window operations.

The structural member can have a mating surface adapted for theattachment of the subfloor or base, framing studs or side molding orbeam, top portion of the structural member to the rough opening. Such amating surface can be flat or can have a geometry designed to permiteasy installation, sufficient support and attachment to the roughopening. The structural member shell can have other surfaces adapted toan exterior trim and interior mating with wood trim pieces and othersurfaces formed into the exposed sides of the structural member adaptedto the installation of metal runners, wood trim parts, door runnersupports, or other metal, plastic, or wood members commonly used in theassembly of windows and doors.

The structural members can be assembled with a variety of knownmechanical fastener techniques. Such techniques include screws, nails,and other hardware. The structural members can also be joined by aninsert into the hollow profile, glue, or a melt fusing technique whereina fused weld is formed at a joint between two structural members. Thestructural members can be cut or milled to form conventional matingsurfaces including 90° angle joints, rabbit joints, tongue and groovejoints, butt joints, etc. Such joints can be bonded using an insertplaced into the hollow profile that is hidden when joinery is complete.Such an insert can be glued or thermally welded into place. The insertcan be injection molded or formed from similar thermoplastics and canhave a service adapted for compression fitting and secure attachment tothe structural member. Such an insert can project from approximately 1to 5 inches into the hollow interior of the structural member. Theinsert can be shaped to form a 90° angle, a 180° extension, or otheracute or obtuse angle required in the assembly of the structural member.Further, such members can be manufactured by milling the mating facesand gluing members together with a solvent, structural or hot meltadhesive. Solvent borne adhesives that can act to dissolve or softenthermoplastic present in the structural member and to promote solventbased adhesion or welding of the materials are known in polyvinylchloride technology. In the welding technique, once the joint surfacesare formed, the surfaces of the joint can be heated to a temperatureabove the melting point of the composite material and while hot, themating surfaces can be contacted in a configuration required in theassembled structure. The contacted heated surfaces fuse through anintimate mixing of molten thermoplastic from each surface. Once mixed,the materials cool to form a structural joint having strength typicallygreater than joinery made with conventional techniques. Any excessthermoplastic melt that is forced from the joint area by pressure inassembling the surfaces can be removed using a heated surface,mechanical routing or a precision knife cutter.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view of an extruded hollow profilestructural member. The member can be an interior or exterior component.The component can be a decking surface member, general purpose board,wall section, wall panel, trim, roofing section, etc. The profile 10includes a wall 11, tongue 12 groove 13 and interior reinforcing web 15.The web 15 can have a curved shape and can be a dual member section inthe form of a “Y” shaped cross section 14. The member 10 can have asurface colored or clear thin decorative cap stock 16. The interior 17of the member 10 comprises the composite as claimed.

FIG. 2 shows a cross sectional view of an extruded C shaped structuralmember profile. The C shaped member 20 has a wall section 21 andextending portions 22 and 22 a formed at right angles to the wall 21.The interior 23 of the member 20 comprises the composite as claimed. Themember 20 can have a surface colored or clear thin decorative cap stock24.

FIG. 3 shows a cross sectional view of an extruded I Beam shapedstructural member profile. The I beam shaped member 30 has a wallsection 31 and extending portions 32, 32 a, 32 b and 32 c formed atright angles to the wall 21. The interior 33 of the member 30 comprisesthe composite as claimed. The member 30 can have a surface colored orclear thin decorative cap stock 34.

The structural member can have a wall thickness of at least 0.5 mm, canbe about 0.8 mm to 5 cm or can be about 1 mm to 4 mm in thickness andcan be manufactured using any typical thermoplastic forming operation.Preferred forming processes include extrusion and injection molding.

While the above specification shows an enabling disclosure of thecomposite technology of the invention, other embodiments of theinvention may be made with the claimed materials. Accordingly, theinvention is embodied in the claims hereinafter appended.

The claims may suitably comprise, consist of, or consist essentially of,or be substantially free or free of any of the disclosed or recitedelements. The claimed technology is illustratively disclosed herein canalso be suitably practiced in the absence of any element which is notspecifically disclosed herein. The various embodiments described aboveare provided by way of illustration only and should not be construed tolimit the claims attached hereto. Various modifications and changes maybe made without following the example embodiments and applicationsillustrated and described herein, and without departing from the truespirit and scope of the following claims.

We claim:
 1. A composite comprising a discontinuous phase dispersed in acontinuous polymer phase: (a) the discontinuous phase comprising afiber, the fiber free of a particulate, the majority of the fiber havinga length greater than about 1 mm, a diameter greater than about 0.8microns and an aspect ratio greater than about 90, the fiber having anexterior coating comprising an interfacial modifier; and (b) thecontinuous phase comprising a vinyl polymer or condensation polymer;wherein the discontinuous fiber phase comprises at least one packingfraction of the fiber phase greater than about 40 wt. % of the compositeand the composite has a flexural modulus as measured by ASTM D790 ofgreater than 8 GPa.
 2. The composite of claim 1 wherein the fibercomprises a natural or synthetic fiber.
 3. The composite of claim 1wherein the fiber comprises a glass or carbon.
 4. The composite of claim1 wherein the fiber comprises a cellulosic fiber or flax.
 5. Thecomposite of claim 1 wherein the polymer comprises a vinyl polymer. 6.The composite of claim 1 wherein the discontinuous phase comprises about90 to 40 weight-% of the fiber.
 7. The composite of claim 1 wherein theinterfacial modifier is present in an amount of about 0.005 to 8 wt.-%in the composite.
 8. The composite of claim 1 wherein the fibercomprises a combination of a cellulosic fiber and a glass fiber.
 9. Thecomposite of claim 8 wherein the cellulosic fiber is a wood fiber. 10.The composite of claim 8 wherein there is a major proportion ofcellulosic fiber and a minor proportion of glass fiber.
 11. Thecomposite of claim 8 wherein there are at least two packing fractions ofthe fiber comprising the cellulosic fiber and the glass fiber.
 12. Thecomposite of claim 8 wherein the packing fraction of the fibercomprising the cellulosic fiber is greater than the packing fractioncomprising the glass fiber.